This is the Nikola One, an electric hybrid truck powered by compressed natural gas which the company claims will give it a range of 1,000 miles—all zero emissions.

Nikola Motor Company

The actual Nikola One won't be seen until December 2016, but the company has taken more than 7,000 deposits for the vehicle.

Nikola Motor Company

Out of all of Elon Musk's recent "Master Plan Part Deux," the part that really caught our eye was a short paragraph about a Tesla semi. Much of the rest—solar, autonomous driving, ride-sharing—wasn't exactly unforeseen. But the idea of a heavy duty Tesla electric vehicle took us by surprise and left us scratching our heads. Tesla isn't the only company going after this market; Wrightspeed, Proterra, and BYD are already building heavy duty urban electric vehicles, and Mercedes-Benz is about to enter the fray. The Nikola Motor Company (no connection to Tesla Motors) already has 7,000 orders for a zero-emission heavy duty freight hauler that won't be revealed until December. To find out if our confusion over the Tesla Semi is unwarranted, we spoke to some of the big players in the heavy duty EV market.

Even though heavy duty vehicles only account for about eight percent of US carbon emissions (light duty vehicles make up roughly 20 percent), Wrightspeed CEO Ian Wright says electrifying that sector makes more economic sense. In fact, Wright doesn't think the economics work in favor of electric passenger vehicles. "A Nissan Leaf is twice the price of a Versa and you only save $800 a year," he told Ars, "that's a 20-year payback time."

Wright goes on:

For argument's sake, the cost delta [between a diesel heavy duty truck and an electrified one] is about $150,000. However, you're talking about a vehicle that burns 14,000 gallons a year. So you can save so vastly much more fuel and brake maintenance as well that you're looking at a three-to-four year payback. The scaling properties work in your favor. It costs more to build [a heavy duty] powertrain, but you save so much more in fuel that the economics are compelling. Which is why [we should] do that and not cars; I think people just don't bother to do that calculation.

Wrightspeed recently won a contract to supply the New Zealand cities of Auckland and Wellington with electric buses, and Wright told us his company is also in talks with Mack Trucks to supply an electric powertrain for that company's LR chassis. But Wrightspeed's vehicles—like those from Proterra, BYD, and soon Mercedes-Benz—are optimized for the stop-start grind of urban life, not cruising along the highways at 70mph. And remember, the relationship between speed and drag is non-linear, so you need more energy to move an EV at highway speeds than the 25-35mph of city life.

Proterra CEO Ryan Popple thinks the Tesla Semi could actually be more of an internal project, enabling the company to operate a zero-emissions supply chain. Popple told Ars:

A fairly reasonable idea would be to move battery packs from the Gigafactory downhill to the assembly plant in Fremont, California. The reason I say that could be viable is they're fundamentally transporting battery packs. They could build battery packs and put them into a truck that's optimized for the shipment of those packs, charge them with solar as a way of validating the pack, and transport them at maybe 50 or 60 percent state of charge. Going from east to west in California is generally fairly easy—6000 feet of elevation certainly helps if the elevation is going in the right direction!

But Popple, like us, is skeptical that a long-haul freight electric vehicle makes sense.

In terms of a long-haul semi truck that could pull 80,000-100,000lbs of cargo you're looking at around a megawatt of energy storage. We're moving buses that, with human beings, weigh 40,000lbs. We have a hyper-efficient drivetrain and we're using a city duty cycle, and we're looking at variations of our product that will require between 250-350kWh of energy storage. It would suggest you're going to need two-to-three times the amount of energy storage buses carry if you really want to be in the business of moving freight.

The forthcoming Nikola One class 8 truck will use a gas turbine generator to charge a 320kW battery pack, something the company claims will enable unparalleled range for an electric vehicle. According to Nikola CEO Trevor Milton:

Nikola has engineered the holy grail of the trucking industry. We are not aware of any zero emission truck in the world that can haul 80,000 pounds more than 1,000 miles and do it without stopping. The Nikola One requires only 15 minutes of downtime before heading out for the next 1,000 miles

Meanwhile, Mercedes-Benz unveiled its own electric heavy duty vehicle, the Urban eTruck, at the end of July . As the name suggests, like those buses and garbage trucks it will be focused on cities. The base spec eTruck's 212kWh battery pack gives it a range of 125 miles (200km). As for Tesla, we'll have to wait until 2017 to find out whether the Tesla Semi was just an afterthought, an internal project tied to the Gigafactory, or if the plan really is to build and sell a range of electric freight carriers.

218 Reader Comments

I was thinking a bit about this when I saw the Master plan 2.0 too. I imagined autonomous long range trucks going at the minimum speed on the freeway (or whatever is most energy efficient...) and doing battery swaps ever few hundred miles. If you're not paying a driver, and the freight moves 24 hours a day, who cares if it drives a bit slower or stops frequently to swap batteries?

By running slower you're effectively losing capacity and cargo also takes longer to reach their destination.

I think you missed the part of moving 24 hours a day. Human drivers are limited in duration for safety reasons to ~9 to 12 hours per day (varies by country and the specific regs). So a human driver driving 12 hours @ 65 mph = 780 miles per day. A 1500 mile trip would take ~2 days.

A fully automated vehicle could travel 24 hours a day. Even if it moved slower say 55 mph to reduce energy costs (drag is the square of speed so 55 mph is 30% less energy due to drag it could travel further. Let's say it has only a 200 mile range between rechargers and lets say something "slow" like a supercharger was used instead of a quick battery swap. So 1500 miles would require 1500/55 = 28 hours + another say 40 minutes * 8 = 5 hours for recharging.

Despite going slower and taking recharging breaks more often your cargo would get there 15 hours earlier. That is the power of a self driving truck.

Look, they can't even get the fully automated four wheelers right, and we're going to unleash driverless 80.000 pound semis onto the highway?

The first time it crushes a family of four in a minivan, that venture will be picked apart by an army of lawyers.

10 year to fully automated semis? Prove it. Oh, but then we'd actually have to wait, you know, ten actual years wouldn't we? Pretty bulletproof defense there. Have you ever seen how many of them are out there on the road, or do you not get that far from your cubicle and your computer and smartphone?

In short, as far as the "driverless" model of full automation for motor vehicles traveling at high speeds, you need a hell of a lot more than "better software algorithms", that's just how people who write software think. You need an accommodating infrastructure, everyone's got to be in on the game since everyone will be sharing the road. Have you seen the roads lately? They suck, but god forbid we raise taxes to upgrade our infrastructure to one that might accommodate dedicated automated vehicle routing, we'd rather wage wars so politicians can crow that they're "keeping us safe".

I was thinking a bit about this when I saw the Master plan 2.0 too. I imagined autonomous long range trucks going at the minimum speed on the freeway (or whatever is most energy efficient...) and doing battery swaps ever few hundred miles. If you're not paying a driver, and the freight moves 24 hours a day, who cares if it drives a bit slower or stops frequently to swap batteries?

By running slower you're effectively losing capacity and cargo also takes longer to reach their destination.

I think you missed the part of moving 24 hours a day. Human drivers are limited in duration for safety reasons to ~9 to 12 hours per day (varies by country and the specific regs). So a human driver driving 12 hours @ 65 mph = 780 miles per day. A 1500 mile trip would take ~2 days.

A fully automated vehicle could travel 24 hours a day. Even if it moved slower say 55 mph to reduce energy costs (drag is the square of speed so 55 mph is 30% less energy due to drag it could travel further. Let's say it has only a 200 mile range between rechargers and lets say something "slow" like a supercharger was used instead of a quick battery swap. So 1500 miles would require 1500/55 = 28 hours + another say 40 minutes * 8 = 5 hours for recharging.

Despite going slower and taking recharging breaks more often your cargo would get there 15 hours earlier. That is the power of a self driving truck.

Look, they can't even get the fully automated four wheelers right, and we're going to unleash driverless 80.000 pound semis onto the highway?

The first time it crushes a family of four in a minivan, that venture will be picked apart by an army of lawyers.

10 year to fully automated semis? Prove it. Oh, but then we'd actually have to wait, you know, ten actual years wouldn't we? Pretty bulletproof defense there. Have you ever seen how many of them are out there on the road, or do you not get that far from your cubicle and your computer and smartphone?

I didn't say 10 years I didn't say any number of years. Eventually it will happen. I was just pointing out the prize for commercial trucking. A commercial truck driver is hours limited and an automated vehicle is not. It also doesn't get bored "refueling" every couple hours unlike passengers. It will gladly run 24/7 stopping every couple hundred miles. Thus it can cover a very large range even with modest battery and lower speed.

Electric trucks would be ideal in an infrastructure where government intervention and regulations hadn't gutted the railroad infrastructure (more so in the Northeastern US than anyplace else). The best solution would be railroads for the majority of long-haul freight, filtering down to localized hubs for transfer to trucks for local delivery. Heck, New York Central Railroad devised a system of sub-containers (5 could be carried per railroad car) way back in 1922. It would have been ideally suited to electric shuttle-trucks.

I was doing the math on this. Basically, every 28' of trailer provides 1kw at 20% efficiency. Your typical semi is 56', so that's 2kw of generation from the top of the trailer.

I don't know if that's enough to overcome drag and recharge the battery at the same time. Stop-and-go would suck, but you're probably at peak generation ratio.

I need more numbers on what it actually takes to accelerate a semi. I wasn't able to get good HP numbers, which I don't think is relevant anyway, but the torque is there. It's just a matter of how fast can you charge vs how fast you can drain.

Not close to enough with today's efficiency. It could marginally boost range. At highway speeds most of the energy is going to be overcoming wind resistance. It looks like a semi is something on the order of 600W/mi at highway speeds.

2KW would be the panels peak output. Average insolation is 4 hours (equivalent of 4 hours of peak sunlight but spread out over 10-12 hours). So 2KW system might get you 8kWh of generation in a driving day or about 13 additional miles. Probably not worth it at today's solar prices but if you could get solar dirt cheap (I mean $0.05 to $0.10 per watt) then maybe. Would be kinda crazy what you could do with cheap 60% efficient panels.

It might be more useful in applications at lower speed and less mileage (think UPS van). A UPS truck might only drive 200 miles in a day and at lower speeds maybe you get 20 miles. 10% more range (or 10% less expensive & heavy batteries). Might be worth it but sometimes simple is better.

The thing about semis.... They spend a lot of time on the highway, whichbare generally clear of tree cover, and are taller than other vehicles so they don't compete for light. UPS trucks are tall, but are easily converted my trees ans semis. It still may be a usable amount of light.

Electric trucks would be ideal in an infrastructure where government intervention and regulations hadn't gutted the railroad infrastructure (more so in the Northeastern US than anyplace else). The best solution would be railroads for the majority of long-haul freight, filtering down to localized hubs for transfer to trucks for local delivery. Heck, New York Central Railroad devised a system of sub-containers (5 could be carried per railroad car) way back in 1922. It would have been ideally suited to electric shuttle-trucks.

Light freight hauling rail build out would help enormously, and something like that lends itself to automation and electric power much better.

However, we don't do things in a logical pattern, we do things by politics and money, not necessarily in that order. It's all helter-skelter, cruft on top of cruft for 150 years.

I was thinking a bit about this when I saw the Master plan 2.0 too. I imagined autonomous long range trucks going at the minimum speed on the freeway (or whatever is most energy efficient...) and doing battery swaps ever few hundred miles. If you're not paying a driver, and the freight moves 24 hours a day, who cares if it drives a bit slower or stops frequently to swap batteries?

By running slower you're effectively losing capacity and cargo also takes longer to reach their destination.

I think you missed the part of moving 24 hours a day. Human drivers are limited in duration for safety reasons to ~9 to 12 hours per day (varies by country and the specific regs). So a human driver driving 12 hours @ 65 mph = 780 miles per day. A 1500 mile trip would take ~2 days.

A fully automated vehicle could travel 24 hours a day. Even if it moved slower say 55 mph to reduce energy costs (drag is the square of speed so 55 mph is 30% less energy due to drag it could travel further. Let's say it has only a 200 mile range between rechargers and lets say something "slow" like a supercharger was used instead of a quick battery swap. So 1500 miles would require 1500/55 = 28 hours + another say 40 minutes * 8 = 5 hours for recharging.

Despite going slower and taking recharging breaks more often your cargo would get there 15 hours earlier. That is the power of a self driving truck.

I hope that's not fresh fish or veggies you got in that truck.. 32h is not that far away from 12h+sleep+12h, is it?.. Imagine the supercharger for trucks.. 5 battery-monsters lined up, each one ready to receive 1MWh... a small town nearby goes dark for 40 minutes

The optimum solution in use right now seems to be a rail track + JB Hunt's Intermodal.

Of course they are more efficient. Brayton cycle is more efficient than otto cycle.

Bull. a simple gas turbine is less efficient than an equivalently-powered Otto or Diesel cycle engine. it will consume a greater amount of fuel per hp-hr. And at part load, they're horrifically inefficient since the lower rotating speed tanks the engine's pressure ratio.

Quote:

It is the reason essentially all powerplants use turbines rather than combustion engines.

feh? you're confusing multiple things here. 1, a gas turbine engine is a combustion engine. 2, power plants have typically used Rankine cycle steam turbines, with the working fluid (water) heated either by coal, petroleum/nat. gas, or fission. 3, power plants using gas turbines used COMBINED CYCLE COMBINED CYCLE COMBINED CYCLE* to reach high efficiencies. 4, gas turbines are a better fit for the high required power levels because they're simpler and less failure prone than an equivalently powerful piston engine.

Quote:

The big problem with turbines for transportation isn't a lack of efficiency. The two major problems is first a turbine is best operating at a fixed speed.

FIXED LOAD.FIXED LOAD.FIXED LOAD.

and yes, efficiency is the problem because at anything less than 100% rated load they are horribly inefficient. They're not much different than piston engines in that increasing the pressure ratio (analagous to increasing the compression ratio in a piston engine) improves efficiency. However with a piston engine, the compression/expansion ratio is the same regardless of engine load or speed. With a gas turbine, the pressure ratio drops substantially at lower engine load/speed, which sends its efficiency into the gutter. and as a prime mover, a gas turbine would almost never be operating at 100% load.

Quote:

A generator powered turbine constantly recharging a battery pack makes that less of an issue. The motive engine than can draw from the battery back However the real killer for making a turbine in vehicle applications is making a small robust yet still cost effective turbine is difficult. Material science may be finally breaking that barrier.

no, the real killer with a gas turbine will be emissions. they have high NOx output (like diesels) but unlike a diesel the sheer amount of exhaust gas flow will make aftertreatment difficult. Look at all of the catalysts and filters diesels have to exhale through. A turbine would be very unhappy trying to push its exhaust through them.

and as for the other comment, there's no "materials science" breakthrough needed. there are millions of small turbines out there in cars today, strapped to the sides of gas and diesel engines.

Yes, a turbocharger is a gas turbine, just one which has another engine as its gas generator.

* sorry to yell, but you people keep glossing over this. reaching high efficiency requires combined-cycle operation where the exhaust heat/reheat is used to generate steam for a steam turbine, which then runs another generator.

I was thinking a bit about this when I saw the Master plan 2.0 too. I imagined autonomous long range trucks going at the minimum speed on the freeway (or whatever is most energy efficient...) and doing battery swaps ever few hundred miles. If you're not paying a driver, and the freight moves 24 hours a day, who cares if it drives a bit slower or stops frequently to swap batteries?

By running slower you're effectively losing capacity and cargo also takes longer to reach their destination.

I think you missed the part of moving 24 hours a day. Human drivers are limited in duration for safety reasons to ~9 to 12 hours per day (varies by country and the specific regs). So a human driver driving 12 hours @ 65 mph = 780 miles per day. A 1500 mile trip would take ~2 days.

A fully automated vehicle could travel 24 hours a day. Even if it moved slower say 55 mph to reduce energy costs (drag is the square of speed so 55 mph is 30% less energy due to drag it could travel further. Let's say it has only a 200 mile range between rechargers and lets say something "slow" like a supercharger was used instead of a quick battery swap. So 1500 miles would require 1500/55 = 28 hours + another say 40 minutes * 8 = 5 hours for recharging.

Despite going slower and taking recharging breaks more often your cargo would get there 15 hours earlier. That is the power of a self driving truck.

All good until the truck fails to see a car crossing the road because the white exterior matched the sky.

I wonder if the (little used) easy/fast battery replacement feature of the Model S could come into play here for the big trucks? If the battery is easily and quickly swappable, couldn't you have stations for that purpose every five hundred miles (or so), along with battery charging for the swapped out packs? Along the sun-belt, it could even be solar powered (mostly).

What happens when my 500 mile truck is 450 miles into its trip and snow shuts down the road for 2 days?

I have a 1,400 mile range and do not push it past 1,000 for this reason...

Is it doable? Yes...

Are they thinking like a driver? No....

In your scenario, for 2 days the battery isn't used because the truck isn't moving. Unlike a diesel, an electric doesn't run its motor constantly when it's not moving.

He's just afraid of change. That's all. it is obvious to anyone paying attention.

Big shock awaits in ~10 years (or less?) when most professional driving jobs simply disappear forever.

Here we go again. 10 years is the new "week to 10 days". People who utter this fantasy just tip their hand that they have no idea what they are talking about. Automation of freight hauling as well as passenger cars will proceed and develop in fits and starts, but those OTR driver jobs are not going to disappear in 10 years.

Trains still have drivers and are not automated, but truck drivers will loose their jobs in 10 years... I don't know what drugs these people take, but please stop and think for a second.

They may lose their jobs as drivers, but I wouldn't be surprised still seeing them sit in their trucks, doing office work on laptops, organizing loading/unloading cargo and overseeing all the clever machinery. You will need to have people around for quite a while, I think. Even if they won't be used as driving bio-robots.

Of course they are more efficient. Brayton cycle is more efficient than otto cycle.

Bull. a simple gas turbine is less efficient than an equivalently-powered Otto or Diesel cycle engine. it will consume a greater amount of fuel per hp-hr. And at part load, they're horrifically inefficient since the lower rotating speed tanks the engine's pressure ratio.

Quote:

It is the reason essentially all powerplants use turbines rather than combustion engines.

feh? you're confusing multiple things here. 1, a gas turbine engine is a combustion engine. 2, power plants have typically used Rankine cycle steam turbines, with the working fluid (water) heated either by coal, petroleum/nat. gas, or fission. 3, power plants using gas turbines used COMBINED CYCLE COMBINED CYCLE COMBINED CYCLE* to reach high efficiencies. 4, gas turbines are a better fit for the high required power levels because they're simpler and less failure prone than an equivalently powerful piston engine.

Quote:

The big problem with turbines for transportation isn't a lack of efficiency. The two major problems is first a turbine is best operating at a fixed speed.

FIXED LOAD.FIXED LOAD.FIXED LOAD.

and yes, efficiency is the problem because at anything less than 100% rated load they are horribly inefficient. They're not much different than piston engines in that increasing the pressure ratio (analagous to increasing the compression ratio in a piston engine) improves efficiency. However with a piston engine, the compression/expansion ratio is the same regardless of engine load or speed. With a gas turbine, the pressure ratio drops substantially at lower engine load/speed, which sends its efficiency into the gutter. and as a prime mover, a gas turbine would almost never be operating at 100% load.

Quote:

A generator powered turbine constantly recharging a battery pack makes that less of an issue. The motive engine than can draw from the battery back However the real killer for making a turbine in vehicle applications is making a small robust yet still cost effective turbine is difficult. Material science may be finally breaking that barrier.

no, the real killer with a gas turbine will be emissions. they have high NOx output (like diesels) but unlike a diesel the sheer amount of exhaust gas flow will make aftertreatment difficult. Look at all of the catalysts and filters diesels have to exhale through. A turbine would be very unhappy trying to push its exhaust through them.

and as for the other comment, there's no "materials science" breakthrough needed. there are millions of small turbines out there in cars today, strapped to the sides of gas and diesel engines.

Yes, a turbocharger is a gas turbine, just one which has another engine as its gas generator.

* sorry to yell, but you people keep glossing over this. reaching high efficiency requires combined-cycle operation where the exhaust heat/reheat is used to generate steam for a steam turbine, which then runs another generator.

It is very likely that it would be running a fixed load, and only turning on when the battery is close to flat, and running till the battery is topped up. That makes more sense than load following since they have a 320kWh battery.

* sorry to yell, but you people keep glossing over this. reaching high efficiency requires combined-cycle operation where the exhaust heat/reheat is used to generate steam for a steam turbine, which then runs another generator.

No it doesn't. Single cycle gas turbines have efficiencies reaching 46% and that isn't just chemical to mechanical efficiency but chemical to electrical. So if you are comparing it to the shaft output of a diesel motor be sure reduce it by the mechanical to electrical conversion efficiency.

Yes combined cycle is even MORE efficient because it is reusing some of that waste heat but even in a typical 60% efficient combined cycle turbine, the primary turbine is a very high efficiency (42% to 47%) turbine. The remainder of the thermal energy (~50%) passes to the steam boiler which is about 30% efficient and thus (0.5*0.3 = 0.15) captures another 15%. ~45% from primary turbine and another 15% from the secondary is how you get a 60% combined cycle output.

Take a look at your average diesel generator for backup power. Efficiency (chemical to electrical) is somewhere on the order of 33%.

I was thinking a bit about this when I saw the Master plan 2.0 too. I imagined autonomous long range trucks going at the minimum speed on the freeway (or whatever is most energy efficient...) and doing battery swaps ever few hundred miles. If you're not paying a driver, and the freight moves 24 hours a day, who cares if it drives a bit slower or stops frequently to swap batteries?

By running slower you're effectively losing capacity and cargo also takes longer to reach their destination.

I think you missed the part of moving 24 hours a day. Human drivers are limited in duration for safety reasons to ~9 to 12 hours per day (varies by country and the specific regs). So a human driver driving 12 hours @ 65 mph = 780 miles per day. A 1500 mile trip would take ~2 days.

A fully automated vehicle could travel 24 hours a day. Even if it moved slower say 55 mph to reduce energy costs (drag is the square of speed so 55 mph is 30% less energy due to drag it could travel further. Let's say it has only a 200 mile range between rechargers and lets say something "slow" like a supercharger was used instead of a quick battery swap. So 1500 miles would require 1500/55 = 28 hours + another say 40 minutes * 8 = 5 hours for recharging.

Despite going slower and taking recharging breaks more often your cargo would get there 15 hours earlier. That is the power of a self driving truck.

All good until the truck fails to see a car crossing the road because the white exterior matched the sky.

You can be guaranteed that one profession that won't "loose their jobs" because of this will be lawyers.

How can it make energy efficiency wise sense to power the electric motor of a truck with electricity, generated by a generator. powered with gas?

To my humble knowledge it would be more efficient to use the combustion energy of the gas directly to propel the vehicle instead of converting it in the first step to electric energy so that in the second step the so produced electric energy can be converted in an electro motor in kinetic energy to propels the truck.

Zero emissions by burning gas is of course impossible.

Are you referring to a hybrid engine here or using electricity from the grid to charge EVs?

I was doing the math on this. Basically, every 28' of trailer provides 1kw at 20% efficiency. Your typical semi is 56', so that's 2kw of generation from the top of the trailer.

I don't know if that's enough to overcome drag and recharge the battery at the same time. Stop-and-go would suck, but you're probably at peak generation ratio.

Huh? No way. 2 kW is about 3 hp. Probably not enough to pull out of a pothole.

Now all we need are semis on autopilot

More seriously, I think the long haul issue could be solved well by catenaries. These would recharge the batteries between local deliveries so there would be no charge downtime and no need to park next to a charging station overnight.

You're comparing storage to power rating. The Tesla Model S (in some configs) has a 90kWh (note the 'h' for 'hours' battery (storage) but makes roughly 500hp of force from its motors, or about 375kW of force.

You are correct that, in euzeka's example, 1 - 2kWh of solar power generation won't be enough to 'drive' anything, but it will definitely be enough to add a few percentage points of efficiency to the system. Whether the extra weight or cost allows that benefit to remain is a different story, of course.

Normally, the idea of putting solar on a *car* is a boondoggle. The car is on the road a small percentage of the time and there's not a lot of flat surface and the total power to be generated is a rounding error. Plus aesthetics. But on a semi trailer ... that might actually work. They sit outside all day, and you've got a flat surface with no aesthetic concerns. It's probably not going to be enough to sustain the truck alone, but if it extends the internal battery pack, hmm, it's possible the numbers might work out.

Biggest issue is going to be that most semi's carry standardized shipping containers that aren't permanently matched to the truck. And sometimes they get shipped across the world. So, the operational model could be a deal-breaker.

"Most" semis are not carrying shipping containers. It's very inefficient to drag shipping containers around. They are heavier and smaller than regular trailers. Goods spend as big a mileage percentage as possible in containers on ships and trains, but as little percentage in containers on the road as possible. Companies move goods into standard trailers as close to the ship/rail terminal as they can.

And if the solar is mostly being utilized when the trailer is standing still, then what's the point of attaching it to the trailer, in the first place? Put the solar panels on the warehouse roof(s), instead.

Of course they are more efficient. Brayton cycle is more efficient than otto cycle.

Bull. a simple gas turbine is less efficient than an equivalently-powered Otto or Diesel cycle engine. it will consume a greater amount of fuel per hp-hr. And at part load, they're horrifically inefficient since the lower rotating speed tanks the engine's pressure ratio.

Quote:

It is the reason essentially all powerplants use turbines rather than combustion engines.

feh? you're confusing multiple things here. 1, a gas turbine engine is a combustion engine. 2, power plants have typically used Rankine cycle steam turbines, with the working fluid (water) heated either by coal, petroleum/nat. gas, or fission. 3, power plants using gas turbines used COMBINED CYCLE COMBINED CYCLE COMBINED CYCLE* to reach high efficiencies. 4, gas turbines are a better fit for the high required power levels because they're simpler and less failure prone than an equivalently powerful piston engine.

Quote:

The big problem with turbines for transportation isn't a lack of efficiency. The two major problems is first a turbine is best operating at a fixed speed.

FIXED LOAD.FIXED LOAD.FIXED LOAD.

and yes, efficiency is the problem because at anything less than 100% rated load they are horribly inefficient. They're not much different than piston engines in that increasing the pressure ratio (analagous to increasing the compression ratio in a piston engine) improves efficiency. However with a piston engine, the compression/expansion ratio is the same regardless of engine load or speed. With a gas turbine, the pressure ratio drops substantially at lower engine load/speed, which sends its efficiency into the gutter. and as a prime mover, a gas turbine would almost never be operating at 100% load.

Quote:

A generator powered turbine constantly recharging a battery pack makes that less of an issue. The motive engine than can draw from the battery back However the real killer for making a turbine in vehicle applications is making a small robust yet still cost effective turbine is difficult. Material science may be finally breaking that barrier.

no, the real killer with a gas turbine will be emissions. they have high NOx output (like diesels) but unlike a diesel the sheer amount of exhaust gas flow will make aftertreatment difficult. Look at all of the catalysts and filters diesels have to exhale through. A turbine would be very unhappy trying to push its exhaust through them.

and as for the other comment, there's no "materials science" breakthrough needed. there are millions of small turbines out there in cars today, strapped to the sides of gas and diesel engines.

Yes, a turbocharger is a gas turbine, just one which has another engine as its gas generator.

* sorry to yell, but you people keep glossing over this. reaching high efficiency requires combined-cycle operation where the exhaust heat/reheat is used to generate steam for a steam turbine, which then runs another generator.

Thank you very much for your post it makes me understand a few things much better. However it makes me even more think that an electro-gas turbine hybrid propulsion system is not the real deal.

I mean the only reason for the gas turbine is to extand the range of the vehicle because batteries can't store enough energy but therefore in addition to the electric propulsion system a costly parallel gas turbine/electric generator system has to be built in the vehicle and maintained and carried around - when it is not in use it is just useless weight.

And why do they want to charge the battery with a gas turbine when a gas pistone engine would be more efficient?

I wonder if the (little used) easy/fast battery replacement feature of the Model S could come into play here for the big trucks? If the battery is easily and quickly swappable, couldn't you have stations for that purpose every five hundred miles (or so), along with battery charging for the swapped out packs? Along the sun-belt, it could even be solar powered (mostly).

What happens when my 500 mile truck is 450 miles into its trip and snow shuts down the road for 2 days?

I have a 1,400 mile range and do not push it past 1,000 for this reason...

Is it doable? Yes...

Are they thinking like a driver? No....

In your scenario, for 2 days the battery isn't used because the truck isn't moving. Unlike a diesel, an electric doesn't run its motor constantly when it's not moving.

Though electric long haul trucks seem a bit ambitious now I'm glad that people are already working on them. I would think that hybrids would have a better chance of success for this role in the near term though.

All they need to do is solve the city problem. Loud, barking trucks are the bane of city living. All electric short range semi's can haul the freight the last mile(s) to actual delivery. This would allow all-night delivery, help ease congestion, noise pollution, etc.

They can keep the gas guzzlers for the long hauls...sound familiar?

Umm, sorry to disappoint you, but most of the noise produced by a semi is tire noise due to hard, high pressure tires. In stop and go traffic, the main source of noise transitions to transmission and air brakes, which you're still going to need.

Lastly, the main reasons we don't have all night delivery is because of rest laws for driving relative to the number of available drivers, increased liabilities driving at night, and we already dick the people who unload consumer goods hard enough with late evening / overnight shifts.

The engine is easily 10-20 decibels louder than the transmission or air brakes, especially since the engine is revving through its power band 5-6 times just to get up to 30 mph, while a car or truck might shift twice, and much more quietly.

EV trucks wouldn't need transmissions? Really? They could possibly run with quieter transmissions with fewer gears, but none at all seems to be a dubious claim at best. I mean I appreciate that you straight up invented numbers to back your claim but ok.

Still, there is a shortage of truck drivers available as well as businesses to take overnight deliveries. It's still a selfish, childish remark regarding shaping infrastructure to fit a small segment's desires regardless of the needs of others.

All they need to do is solve the city problem. Loud, barking trucks are the bane of city living. All electric short range semi's can haul the freight the last mile(s) to actual delivery. This would allow all-night delivery, help ease congestion, noise pollution, etc.

They can keep the gas guzzlers for the long hauls...sound familiar?

Umm, sorry to disappoint you, but most of the noise produced by a semi is tire noise due to hard, high pressure tires. In stop and go traffic, the main source of noise transitions to transmission and air brakes, which you're still going to need.

Lastly, the main reasons we don't have all night delivery is because of rest laws for driving relative to the number of available drivers, increased liabilities driving at night, and we already dick the people who unload consumer goods hard enough with late evening / overnight shifts.

The engine is easily 10-20 decibels louder than the transmission or air brakes, especially since the engine is revving through its power band 5-6 times just to get up to 30 mph, while a car or truck might shift twice, and much more quietly.

EV trucks wouldn't need transmissions? Really? They could possibly run with quieter transmissions with fewer gears, but none at all seems to be a dubious claim at best. I mean I appreciate that you straight up invented numbers to back your claim but ok.

They will have transmissions, but probably single speed, which means it would be mechanically much simpler, and you won't be revving multiple times as you speed up. (not like electric cars rev anyway, the sound like bigger toy cars)

Most electric cars on the market now have single speed transmissions, such as the model S, model X, and Nissan Leaf. The whole "transmission" is just a gear reduction to bring motor speeds to reasonable axle speeds.

Also, if you've lived in a large city, you're probably really familiar with the diesel revving noise from busses and trucks. Reducing that would be a pretty large improvement in quality of life to anyone living in non-gated apartment complexes near major highways.

It's funny that Mercedes put camouflage on a box truck, lol. Ooh, I wonder if it's the amg version.

This is a fairly common practice for prototypes/not yet released models. Apparently such designs prevents auto magazines from bothering to take photos since they don't look particularly attractive anyway.

Source: I'm from Ann Arbor, there are tons of cars undergoing their pre-release emissions testing at the national lab here.

But its a semi truck shaped like a box, I think there was some humor meant by the development team. It certainly wasn't done to hide subtle curves and flowing body lines.

Tesla should 1st create an all Tesla all electric transporter for their own vehicles. I see tons of their cars on their way to service tailored behind Ford heavy duty gassers and sometimes powerstrokes. My guess is that cheapest transport is best when you're trying to make a return for your investors even though this approach would pave the way for for much needed experience in transport in stead of jumping all in.

I was thinking a bit about this when I saw the Master plan 2.0 too. I imagined autonomous long range trucks going at the minimum speed on the freeway (or whatever is most energy efficient...) and doing battery swaps ever few hundred miles. If you're not paying a driver, and the freight moves 24 hours a day, who cares if it drives a bit slower or stops frequently to swap batteries?

By running slower you're effectively losing capacity and cargo also takes longer to reach their destination.

I think you missed the part of moving 24 hours a day. Human drivers are limited in duration for safety reasons to ~9 to 12 hours per day (varies by country and the specific regs). So a human driver driving 12 hours @ 65 mph = 780 miles per day. A 1500 mile trip would take ~2 days.

A fully automated vehicle could travel 24 hours a day. Even if it moved slower say 55 mph to reduce energy costs (drag is the square of speed so 55 mph is 30% less energy due to drag it could travel further. Let's say it has only a 200 mile range between rechargers and lets say something "slow" like a supercharger was used instead of a quick battery swap. So 1500 miles would require 1500/55 = 28 hours + another say 40 minutes * 8 = 5 hours for recharging.

Despite going slower and taking recharging breaks more often your cargo would get there 15 hours earlier. That is the power of a self driving truck.

Look, they can't even get the fully automated four wheelers right, and we're going to unleash driverless 80.000 pound semis onto the highway?

The first time it crushes a family of four in a minivan, that venture will be picked apart by an army of lawyers.

10 year to fully automated semis? Prove it. Oh, but then we'd actually have to wait, you know, ten actual years wouldn't we? Pretty bulletproof defense there. Have you ever seen how many of them are out there on the road, or do you not get that far from your cubicle and your computer and smartphone?

In short, as far as the "driverless" model of full automation for motor vehicles traveling at high speeds, you need a hell of a lot more than "better software algorithms", that's just how people who write software think. You need an accommodating infrastructure, everyone's got to be in on the game since everyone will be sharing the road. Have you seen the roads lately? They suck, but god forbid we raise taxes to upgrade our infrastructure to one that might accommodate dedicated automated vehicle routing, we'd rather wage wars so politicians can crow that they're "keeping us safe".

Still, there is a shortage of truck drivers available as well as businesses to take overnight deliveries. It's still a selfish, childish remark regarding shaping infrastructure to fit a small segment's desires regardless of the needs of others.

This is a rather mysterious comment to me. Are you saying more businesses should have somebody around to take overnight deliveries? But that it's a selfish desire of yours, because truck drivers are a really small segment compared to all the businesses and people living in cities, and that the small segment's desires for how infrastructure works shouldn't override the population's desires for less noise pollution and for businesses that don't want to hire a night shift?

The article is essentially right for today. But, as battery capacity increases and price decreases its pretty obvious that electric cars will be very competitive with gas even at the lower end ($ 30K) and long haul trucks will make great economic sense. Until then, then electric buses should have the best ROI because of regenerative brakes to recover energy in a stop intense environment. The statement "And remember, the relationship between speed and drag is non-linear, so you need more energy to move an EV at highway speeds than the 25-35mph of city life." is only true above 30 mph; it is essentially linear up to 30 mph. This is related to laminar vs turbulent flow. So turbulence is unavoidable above 30 mph hence long haul electric trucks really don't make a lot of sense right now because of current energy densities. And ditto for cars at lower price points.

Is there a study on air quality impact of "Heavy" trucks in urban environments? I could see electric trucks being great for Expediter or short haul situations and deliveries in urban environments. Like the above commentors for moving from container ships to rail tracks. Or from rail yards to local warehouses and from local warehouse to retail space. Heck you could even install the chargers at the docks for these vehicles and potentially add a reasonable amount of range while unloading or loading.

Not to mention that there are a number of small "lot mover" trucks that could be electric instead of gas or diesel.

That's what I was thinking. If you had local charging in areas where the delivery truck is operating anyway, then while its being loaded/unloaded it can also be getting a nice added charge. Heck, battery swaps for this kind of setup would work MUCH better than for passenger vehicles, where they don't really make that much sense.

Why would they need a transmission? EV motors offer very flat power curves* (unlike any internal combustion engines which delivers power in a very very very narrow speed range. Transmissions are simply a way to bypass that limitation of internal combustion engines a limitation which doesn't exist in modern AC induction motors.

Another advantage of EVs is that the motor is pretty damn cheap. The batteries are expensive but the cheap cost of the motor means using two (or even four) motors in a vehicle is viable where it simply isn't for internal combustion (cheap "battery" and expensive motors). Tesla's dual motor vehicles actually very higher "fuel" economy because each motor is optimized for a different role by selecting motors with different power bands.

* Very nearly flat but not perfect they tend to fall off at the high end but really the only vehicles which would need a transmission would be race cars (which need to go from say 0 mph to above 160 mph) and it is difficult to find an EV which can support a RPM range that would accommodate that without loss of power so a 2 gear transmission is normally used. First gear is something like 0 to 100 mph and second gear is everything past that.

Wright doesn't think the economics work in favor of electric passenger vehicles. "A Nissan Leaf is twice the price of a Versa and you only save $800 a year," he told Ars, "that's a 20-year payback time."

Factor in the costs of all externalities that are currently unaccounted for in the cost of a vehicle and fuel and get back to me.

In the long run, electric cars are the only thing that really makes sense. The problem is still one of power delivery and storage. We really need a new form of battery at least 5x the power density if we're going to replace fuel cars with electric cars.

This is kinda OT, I know this isn't the same kind of truck mentioned in the article, but any sort of electric vehicle with the torque needed to tow and haul interests me.

Where I live, every other truck on the road is a pickup truck. I seriously doubt there will be any sort of meaningful EV penetration in certain parts of the US until Ford/GM/Chrysler/someone managed to develop an electric truck that can compare with gasoline and diesel trucks.

There are a few reasons why you don't hear much about light duty EV trucks/SUVs. First, the market is anchored by people who will never accept anything other than a diesel/big block V8. These people don't give a shit about emissions or fuel economy.

Then there are the farmers, who are already hauling around diesel for their farm implements. They're going to stick with diesel, because they can pump diesel from their pickup to their tractor in a pinch, they have it delivered to their farms in bulk, and diesel is a proven technology. These guys overlap a bit with the first group.

Finally, there's the light duty fleet vehicle. This is where EV trucks make sense, and there is some work being done in this space. My utility is experimenting with EV light duty bucket trucks. Right now the battery is only good for powering the bucket and lifting/lowering the stabilizers, but the goal is to work with Ford/GM to get us a few dozen of these things for metro areas where they can be efficiently used.

But yeah, most of the US light duty truck segment isn't going to buy an EV truck because it isn't "cool," or the market is too resistant to change.

Eh, I'm not so sure. First of all, farmers care about money, they're businesses, so they could give a crap about some aesthetic preference for 'big V8s' or whatever. If they can run an electric tractor, truck, etc and it saved them money, then that segment is done, you got them. They'll drive their electric pickup into town and love it. Now, that may not happen, or may not happen for a long time, but if you think about tractors, they aren't necessarily a bad target for electrification...

As for rednecks... I think people underestimate. There's a lot of smart people out there that are driving pickup trucks, etc. and might well drive an EV if it provided the right mix of features. Again, that may not be here today, but as the light passenger vehicle market, the short haul market, the buses, etc slowly transition over its likely that EVs are going to become far more of a normal thing. Because they have HUGE advantages in terms of maintenance, etc eventually every segment will yield to the inevitable logic. Finally, the 10% of absolute utter hard core nuts that can't be convinced will die eventually, lol.

I think its quite possible there will just be a tipping point, and once we get there ICEs will simply stop making sense for most purposes. I mean what happens when demand for gasoline falls by 80%? It ain't going to stay dirt cheap, and there aren't going to be pumps on every corner anymore.

I wonder if the (little used) easy/fast battery replacement feature of the Model S could come into play here for the big trucks? If the battery is easily and quickly swappable, couldn't you have stations for that purpose every five hundred miles (or so), along with battery charging for the swapped out packs? Along the sun-belt, it could even be solar powered (mostly).

Put batteries in the trailer which can then charge while the trailer is sat idle as well as having cab batteries.

That seems like it would drastically cut down the flexibility...the trucks aren't permanently "married" to the trailers now, they may drop off one trailer then pick up another from a different place for a return trip.

How can it make energy efficiency wise sense to power the electric motor of a truck with electricity, generated by a generator. powered with gas?

To my humble knowledge it would be more efficient to use the combustion energy of the gas directly to propel the vehicle instead of converting it in the first step to electric energy so that in the second step the so produced electric energy can be converted in an electro motor in kinetic energy to propels the truck.

Zero emissions by burning gas is of course impossible.

You really need to contact the railroads and let them know they have been getting it all wrong for nearly a century

Huh? The reason the large train locomotives are diesel-electric is not to do with energy efficiency. It's because it's too hard to make a clutch and gearbox which lasts any respectable amount of time, given the absolutely huge forces needed to get a heavy freight train moving from stand-still.

I think rdnxl is partially correct that in many cases a series-hybrid is less energetically efficient than a direct drive, but in the case of Nikola One we're talking about the use of a highly efficient gas turbine which can operate at peak efficiency all the time, so in this situation a series hybrid might well make sense.

During the last time this debate raged in an Ars forum I did the research on this. Its debatable. Charge/discharge efficiency for batteries is up now in the 95%+ range, but that still means you lose at least 10% right there for a series hybrid, right off the top. Efficiency of a gas turbine is not bad, but the modern crop of ICEs are actually pretty efficient too.

The upshot is there's a use case for both series and parallel hybrids. Given that most vehicles, particularly passenger vehicles, take on a variety of different driving regimes (IE highway and city driving) the solution for those is not simple to derive. Honda and Toyota, as well as other hybrid makers, have generally settled on parallel drive trains, like the Prius' Hybrid Synergy Drive. For a truck however the equation might well favor a pure serial electric hybrid. Its really beyond the scope of what we can sort out in a forum to know.

The SuperTruck program was able to cut aero drag in half, which looks to be ~120+hp at 55mph based on the Cummins graph. If Tesla can cut misc power requirements by ~50% and rolling resistance by ~15%, they'd be at ~100hp @55mph.

~100hp-hr is ~75kWh, so a SuperTruck style tractor trailer with 400 miles of range would need ~600kWh of batteries. That won't cut it for a person driving long-haul, but I'm guessing it'll work for shorter routes.

I think Tesla can probably improve on the SuperTruck's aerodynamics a bit, but the bigger bang for their buck would be autonomous convoys. The reduction in aero drag from drafting could increase range for the convoy to ~1 mile per kWh of battery capacity. If Tesla's supercharger density is high enough, even if they're governed to 55mph, these trucks might be able to do ~1000-1200+ miles per day because their drive time isn't limited to 11 hours per day. At that point they might be able to compete with some long haul trucking.

Edit - The economics aren't too bad either. 600kWh of batteries at $150/kWh is ~$90,000. If these trucks can drive ~150k miles/year, they'll amortize the cost of the battery pack within 2 years compared to the average truck on the road at 7mpg and diesel at $2.50/gallon.

I was thinking a bit about this when I saw the Master plan 2.0 too. I imagined autonomous long range trucks going at the minimum speed on the freeway (or whatever is most energy efficient...) and doing battery swaps ever few hundred miles. If you're not paying a driver, and the freight moves 24 hours a day, who cares if it drives a bit slower or stops frequently to swap batteries?

The first Active line for Hyperloop will be cargo hauling. Ifthe Hyperloop thing works out, long range hauling will take a hit from that angle too.

Why would a hyperloop freight line beat straight up old fashioned rail? It wouldn't, it won't, and its a silly concept. Rail IS cheaper to build, and most rail cargo isn't that time-sensitive, its bulk materials, etc where traveling cheaply at 60MPH average for 3 days beats the tar out of traveling at 700MPH for 2 hours. Particularly when BOTH need to be transferred to some local truck anyway, which probably adds a day to each one, cutting the high speed advantage drastically.

Its not impossible there could be a specific use case for this, but I find it unlikely that someone is going to spend the vast numbers of $billions that would be needed to realize whatever that specific case is vs just using the existing rail infrastructure, which already goes within a few miles of almost everywhere that's worth going (and is relatively cheap to extend, given that both it and hyperloop have basically the same right-of-way needs).

I disagree. In my country (Australia) we probably have the most established truck driving industry in the world. Drivers here are required, by law, to stop for rest twice in every 8 hour shift, or four times in an 11 hour shift (and you can't do more than 11 hours on the road a full 7 hours break in between). I'm sure most countries have similar rest requirements.

This means you really only need about 3 hours range, which is a lot shorter than 1,000 miles. More like 200 miles in fact.

The real question is what type of infrastructure is required to get a driver back on the road quickly.

Obviously a battery can't be charged in 15 minutes so you'd have to switch cabs - that seems reasonable for large fleets with well established routes (eg, mining freight).

But hydrogen or Nikola's "zero emission" gas engine should all easily fill up in less than the 15 minutes required to stop for a break.

Mind you, Nikola claims to have 1,000 mile range with their truck. So you should be happy with that one.

Quote:

Need >500 Hp and 450ft-lb.

Electric motors have peak power at 0 RPM, which makes them ideally suited to shifting heavy cargo and you can get away with "weaker" engines than a diesel, since there's no clutch required except for gear changes.

Well if you need 2 stops in a 8 hours shift, I think it's doable with superchargers. It means like 3 hours driving - stop - 3 hours driving - stop - 2 hours driving - end of shift. So basically 180 miles on a 3 hours shift.

I agree that battery swap could be interesting, but I don't agree that it would be necessary. I you imagine a battery large enough for something like 500 miles, you're good to go. It means you can easily do a 300 mile shift, then get back 100 or 200 miles with a quick break, easily enough to do a 300 mile shift again.

The beauty of it is you could probably do it with virtually no change to the superchargers : just change the layout so that a semi can park there, and so that you can plug several superchargers to it (the larger the battery, the most power you can actually put in it because you spread it through more cells).

Every manufacturer of long-haul trucks has been experimenting with hybrids and electrics for a decade. Tesla obviously has skills in the area, but the fact remains that there are no class C vehicles that can match the power and cost of diesel after so many years. Short haul, he may have a game plan, but then you have to take into account that a LOT of hauled goods need climate control, which completely blows his power needs sky-high. What I see this doing successfully is moving goods from warehouses on the edge of cities into their target retailers efficiently, at least over a long term. If he does go for long haul trucking, the biggest advantage for him probably won't be the freight distribution business itself - it would be in establishing enough power stations to make electric freight hauling viable, which would also make long-distance consumer electric travel viable for customers who won't pay for that construction expense. Consider the long-haul venture to be a write-off for greater purposes: a reliable network of well-distributed, electrified "truck-stops".

I'm really surprised at Tesla targetting trucks, seems very off with their current high-end consumer brand. Wouldn't be surprised if they deliver a good truck but fail to really sell it to businesses, and then proceed to sell batteries and powertrains to other truck-makers. Would make a lot of sense since they'll have the best economies of scale on batteries if the Gigafactory works as expected.

It is very likely that it would be running a fixed load, and only turning on when the battery is close to flat, and running till the battery is topped up. That makes more sense than load following since they have a 320kWh battery.

Sadly, no it doesn't. Here's the thing. Hauling around that big expensive battery is very expensive, in all ways. It cuts into the cargo capacity, its expensive, etc.

So, the logic becomes to carry more fuel and less battery. That logic means you have to start running your engine more often for shorter periods of time, which turbines are bad at. So there's yet another equation to balance there, in addition to the losses inherent in charge/discharge.

Again, look at the Prius as an example. It has a very small battery, you can't even make 2km on battery power. The engine cycles on and off quite frequently, but because its a standard 4-cycle engine optimized for this kind of use, that's OK. It also obviously couples to a drive train designed to minimize the need to charge and discharge the battery. In essence it operates as an electrically-assisted ICE vehicle. This allows for a very nice efficiency advantage, about 40% better than a straight ICE in the same vehicle, but a gas turbine wouldn't cut it for this use at all.

Again, that doesn't mean a gas turbine (it would be a multi-stage turbine BTW) isn't the correct answer for some types of vehicle, maybe it is. Its just not AT ALL one that is clearly the answer.

Of course they're going for an electric commercial hauler. Hauling is an efficiency game and electric has a huge advantage in that turf. Plus it's green as hell. Imagine thee marketing potential.

If you hit even 40% of the semis in one fell swoop and were able to make them look distinct or have logos on it etc, all the sudden people are seeing them everywhere. Priceless.

There's just too many reasons to list.

+1 - Yes exactly this. Not sure why so many here are waiting for electric to become a wholesale replacement for ICE under every use case. This type of thinking about technology is really quite flawed. We didn't wait until truck and train technology was perfected before we transitioning away from horse drawn carriages.

It is easy to come up with hypotheticals as to why a technology might fail, true innovation is realizing where it might succeed.